(a) Within 35 days following the conclusion of a hearing on an original and an alternative proposal to form a subsidiary district, the commission shall adopt its resolution of determination, which shall do one of the following:
(1) Deny both the original proposal and the alternative proposal.
(2) Approve one proposal and deny the other.
(b) “Alternative proposal,” as used in this section, means an alternative proposal to a subsidiary district proposal as provided for in Section 56861.